Minimally invasive medical techniques are intended to reduce the amount of tissue that is damaged during interventional procedures, thereby reducing patient recovery time, discomfort, and deleterious side effects. Such minimally invasive techniques may be performed through natural orifices in a patient anatomy or through one or more surgical incisions. Through these natural orifices or incisions clinicians may insert interventional instruments (including surgical, diagnostic, therapeutic, or biopsy instruments) to reach a target tissue location. To reach the target tissue location, a minimally invasive interventional instrument may navigate natural or surgically created passageways in anatomical systems such as the lungs, the colon, the intestines, the kidneys, the heart, the circulatory system, or the like. Robotic interventional systems may be used to insert the interventional instruments into the patient anatomy. In existing systems, the length of the interventional instrument extending between the patient and a robotic manipulator is unsupported which may cause the instrument to bend and buckle as it is inserted into the patient anatomy. Deformation of the instrument may damage internal components such as optical fiber shape sensors or endoscopic equipment. Improved systems and methods are needed for guiding and supporting interventional instruments as they are inserted into a patient anatomy to prevent instrument deformation.